Results of the 3rd Germany-Japan Beyond 5G/6G ResearchWorkshop
Masafumi Hashimoto

Director
Innovation Promotion Department
Standardization Promotion Office
National Instituted of Information and Communications Technology

1. Introduction

The National Institute of Information
and Communications Technology (NICT)
is engaged in international exchange on
Beyond 5G/6G research. NICT co-hosted
the 3rd Germany-Japan Beyond 5G/6G
Research Workshop with 6G Platform
Germany, an organization that organizes
6G research projects in Germany.
Dates: February 5 (Mon) to 6 (Tue),
2024
Venue: NICT Innovation Center (15thf loor, Nihombashi Tower,
Tokyo)
Participants: Open to anyone interested
i n B e yond 5G/6G
research activities
The f irst day was the day after“Risshun” (the first day of spring), but
the weather was unexpected, with snow
starting to fall in the afternoon to a few
centimeters in Tokyo. Nonetheless, 75
participants (52 from Japan and 23 from
Germany) participated and engaged in an
enthusiastic exchange of opinions.

2. Review of previous events

This workshop started as a researchlevel international exchange activity
following the exchange of opinions

between Japan’s Ministry of Internal
Affairs and Communications (MIC)
and the German Federal Ministry of
Education and Research (BMBF).
The two countries are working to build
cooperat ive relat ionsh ips bet ween
universities, research institutes, and theprivate sector through Beyond 5G/6G
R& D col laborations. Mr. Takeak i
Matsumoto, Minister for Internal Affairs
and Communications, and Ms. Bettina
Stark-Watzinger, Federa l Ministerof Education and Research, signed a
Memorandum of Cooperation in the fieldof communications technology on May 11,
2023.
The 1 st Germany-Japan Beyond
5G/6G Research Workshop was heldfrom April 24 to 25, 2023 at the NICT
Headquarters in Koganei. The workshop
was attended by 73 participants (51from Japan and 22 from Germany).
From Japan, par ticipants included
researchers from NICT and Beyond
5G R&D Fund commissioned research
institutions, members of the Beyond 5G
Promotion Consortium, representativesof telecommunications carriers, vendors,
and academic societies. From Germany,
participants included representatives

from the BMBF 6G Research Hubs of
6G (6GEM, 6G-Life, 6G-RIC, andOpen6GHub), 6G Platform Germany,
universities, and private companies.
T he f i r s t w ork s hop i nc lu d e dpresentations of research activities
on Beyond 5G/6G in both countries, aposter session, and a panel discussion to
explore the possibilities and directions ofcooperation between Japan and Germany.
In a questionnaire survey conducted after
the event, positive comments were received
such as “the event was very helpful ingiving an idea of the concrete initiatives ofJapan and Germany for Beyond 5G/6G”
and “it provided ample time to discuss withparticipants from Japan and Germany.”
The 2 nd Germany-Japan Beyond
5G/6G Research Workshop was held in
Berlin at the same time as the Berlin 6G
Conference from June 27 to 29, 2023.
The Berlin 6G Conference is an exchange
event that brings together people engaged
in 6G from all over Germany. Despite
being held for the first time, the event
was attended by more than 1,000 people.
From Japan, 12 representatives from the
Beyond 5G R&D Fund commissioned
research institutions, NICT, Beyond 5G
Consortium, and the Japanese Embassy in■ Figure 1: Group photo of participants

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13

Germany participated.
In the plenary session on the first day,Japanese participants took the stage andtook commemorative photos with officials
from the German Federal Ministry of
Education and Research and 6G Platform
Germany. In addition, Dr. Iwao Hosako,
Director General of the Beyond 5G R&D
Promotion Unit at NICT, Mr. Yoji Kishi,
Executive Director of KDDI ResearchInc., and Mr. Takehiro Nakamura,
Director at N T T DoCoMo, who
represented the Beyond 5G Consortium,
each gave a lecture.
The Germany-Japan Beyond 5G/6G
Research Workshop was held as one ofthe parallel sessions of the Berlin 6G
Conference and was attended by morethan 60 participants. There were 13
proposals from both countries on research
themes for cooperation between Japan andGermany that were accepted beforehand.
A representative from the Federal Ministryof Education and Research of Germany
announced that it would provide budget
support for around one year starting fromthe following year for Germany-Japan
R&D collaborative projects. Also, a tour of
the Berlin 6G Conference demonstration

exhibit showcased the various use cases of
6G.

3. Initiatives of the German
and Japanese governments

Lectures were delivered on theinitiatives of the German and Japanese
governments on Beyond 5G/6G. It became
a valuable opportunity to grasp the policy
trends of the MIC and the BMBF.
Mr. Ta k a hiro Tana k a (Deput y
Director, MIC) gave a lecture on Japan’s
Beyond 5G/6G promotion strateg y.
In addition to the R&D and testbed
maintenance that have been carried out
since FY2021, he explained about thelaunch of the 81.2-billion-yen R&D fundin FY2023. He also mentioned that a new
Beyond 5G/6G strategy will be announced
this summer.
M r. K a i B ö r n e r ( V D I / V DE
Innovation + Technik) introduced
Startup Connect, a BMBF initiative
to support start-ups in the f ield of
telecommunications. Four incubators
were set up to provide start-ups withinformation, measurement equipment,
and networking contacts. Start-ups also
receive funding to accelerate the transfer

of research results into the market. He
also mentioned that BMBF and MIC are
discussing ways to implement GermanyJapan cooperation projects. The first phaseof the Germany-Japan cooperation projectwill be presented at the 4th GermanyJapan research workshop to be held in
Berlin in July 2024.
■ Figure 4: Lecture by Mr. Takahiro
Tanaka■ Figure 5: Lecture by Mr. Kai Börner

■ Figure 2: P hoto from the first workshop

4. Panel Discussion■ Figure 3: Photo from the second workshop

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The two-day panel discussions delvedon the possibilities of Germany-Japan
cooperation in research and development
on Beyond 5G/6G. The panelists and theaudience engaged in lively discussions.
1. Overview of the first day
The panelists on the first day were
Prof. Akihiro Nakao (University of Tokyo),Prof. Kei Sakaguchi (Tokyo Tech), Dr.
Takayuki Kuroda (NEC), Mr. Takehiro
Nakamura (NTT DoCoMo), Prof. Aydin
Sezgin (Ruhr University Bochum), Dr.
Renato Cavalcante (Fraunhofer HHI),
and Dr. Szabolcs Malomsoky (Ericsson).
Dr. Kentaro Ishizu (NICT) served as themoderator.
In the discussions, the question of
the importance of using digital twinsin the Beyond 5G/6G era not only for■ Figure 6: Panel discussion on the first day

monitoring but also for services thatinvolve interaction with people wasraised. A participant expressed the viewthat digital twins will undergo gradualadvancement, wherein today’s digital twins
are still in the 0th stage of monitoringand sensing. This will be followed by the
first stage of visualization, the second
stage of optimization, and the third
stage of prediction. He also mentionedthat digital twins could be used to predict
lightning strikes, traffic congestion, andpeople’s health conditions. Initiatives oftelecom operators in using digital twins
to autonomously manage their networks
and increase their resilience were also
introduced, and the use of digital twins
outside of the telecom industry was alsosuggested.
Next, concerns were raised about thesustainability of artificial intelligence (AI)and digital twins as they consume large
amounts of energy. Efforts to develop
lightweight AI with emphasis on Japanese
language processing in Japan were thenintroduced. In addition, the necessity tocontrol the network and reduce power
consumption in accordance with thecommunication demand was pointed out.
The importance of sustainability as well as
the pursuit of performance in the systemdesign of Beyond 5G/6G was also noted.
As AI and machine learning (ML)have become increasingly used in research,
researchers discussed whether they should
focus more on mathematical analysis or
AI/ML data. Some were of the opinion
that since Beyond 5G/6G is AI-native,
young researchers should actively use AI/■ Figure 7: P anel discussion on the second day

ML while keeping in mind the ethicalissues of their use.
Lastly, discussions were held on
potential topics for cooperation between
G er m a ny a nd Jap a n , c onc lud i n gthat resilience, digital twins, energy
consumption, and AI will continue to beconsidered as candidates.
2. Overview of the second day
The panelists on the second day were
Mr. Hideaki Takahashi (Nokia), Dr.
Satoshi Konishi (KDDI Research Inc.),
Dr. Takeshi Matsumura (NICT), Mr.
Yuji Tazaki (Fujitsu), Prof. Andreas Stöhr(Univ. Duisburg-Essen), and Mr. Niels
König (Fraunhofer IPT). Prof. Haris
Gačanin (RWTH Aachen Univ.) served as
the moderator.
First, measures to curb energ yconsumption were discussed. Among themeasures cited were the use of opticalfibers and the transition from centralized
processing to distributed processing.
The ability of NICT’s wireless emulator,
which enables demonstration of a largescale wireless system in a virtual space, tomake system construction efficient was
mentioned.
Next, the fusion of radio and light
was discussed. The difficulty of installing
optical fibers in different sorts of areasin Japan was pointed out, along with thenecessity to strengthen the entire network,
rather than choosing between wireless or
optical, in light of the doubling of traffic
every three years. It was also mentionedthat customers view networks from an endto-end perspective.
With the advent of the new generationsof 4G, 5G, and Beyond 5G/6G, it
was noted that the management ofheterogeneous networks will become
crucial. Efforts to develop a standard thatallows flexible frequency selection at 3GPP
were introduced. Also, the effectiveness ofevaluating the response using AI to avoid
network failures was suggested since theoptimal solution differs from generation to
generation.
Regarding topics for Germany-Japan
cooperation, the panelists have agreed that
research institutes, vendors, and operators
should continue considering issues ofcommon interest.

5. Lectures by researchers

The rich variety of presentations fromresearchers showed that Beyond 5G/6G
can serve as the foundation of all industries
and social activities.
Dr. Tetsuya Ido (NICT) introduced
the Wi-Wi space-time synchronization
technology. For satellites, a technology has
been established to compare time between
UTC (Coordinated Universal Time)and JST (Japan Standard Time) with anaccuracy in nano (10 -9) seconds. Wi-Wi
makes this possible between small wirelessdevices. They are also developing anantenna that reduces the phase error arisingfrom the transmission and reception angles.
Dr. Motoaki Hara (NICT) presented
the development roadmap for an ultracompact atomic clock with a size of 0.5
cc or less and the latest development
progress. He also introduced the cluster
clock infrastructure, in which numerous
communication nodes equipped with

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atomic clocks cooperate to achieve highly
stable and reliable time synchronization,and introduced the new time-series
algorithm required for this technology.
Dr. Ryosuke Isogai (NICT) reported
the success of a demonstration experiment
for transmitting 120 MB of data in about
0.5 seconds, the time it takes for drones topass each other. Two drones were equippedwith IEEE802.15.3e-compliant 60-GHz
wireless devices, and high-frequency
communication was established within the
short period of time that the two drones
passed each other, enabling high-capacity
data transmission.
Mr. Kentaro Tani (NGK Insulators)
introduced a hybrid bonded wafer for subterahertz band antenna. The wafer, which
is made of a silica glass functional layer
and a silicon base substrate directly bonded
together, has low loss characteristics over awide frequency band of 100 GHz or more,
and is resistant to high temperatures andhigh humidity.
D r. Yu s u k e D o h i ( J R E a s t)
introduced the efforts of the Research andDevelopment Center of JR East toward
the utilization of Local 5G and discussed
the necessity of technical and institutional
studies to construct linear wireless areas
such as for railway tracks. The paper by Dr.
Dohi reporting on Local 5G verification
test on Shinkansen Deadhead Line won
the 39 th Telecom System Technology
Award of the Telecommunications
Advancement Foundation.
Mr. Niels König (Fraunhofer IPT)
introduced production research conductedat the 5G-Industry Campus Europe. This
research is aimed at concurrently solving
problems of quality, time, and cost withthe use of 5G. They demonstrated thata 5G multi-sensor platform enabled a5-axis milling machine to accurately create
aircraft engine blades by transmitting datasuch as acceleration, strain, temperature,and humidity.
Mr. Till Witt (NXP Semiconductors)
int roduced Ger ma n in it iat ives inquant um computing. The German
government included 2 billion euros for
R& D on quantum technologies andquantum computing in the budgetary
package for economic stimulus in 2020.
NXP semiconductors is involved inthree governmental projects; namely,
demonstration of a 10-Qbit computer,development of a 50-Qbit prototype
computer, and construction of a modular
platform.

6. Poster session

Japanese and German researchers
engaged in active discussions withparticipants in front of the posters.
The fol low ing poster presentation
overview excludes posters related toresearch presented in the lectures anddemonstrations.
Dr. Tobias Meuser (TU Darmstadt)
presented their experiments with functions
for switching the components of thewireless access network and switching thevarious nodes of the core network by ML
in order to increase the resiliency of 5G
and 6G networks.

■ Figure 8: Lecture from the Japanese side
(Dr. Tetsuya Ido)

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Mr. Michael Weimer (Fraunhofer
FHR) presented their research on joint
communication and sensing ( JCS),
which uses radio waves for wirelesscommunication in combination withsensing. They presented initial results
towards formulating the concept for a longrange OFDM radar for demonstration of
JCS and its required technologies.
Mr. Andreas Bathelt (Fraunhofer
FHR) presented his research on timesynchronization for JCS. He discussed
a basic algorithm that creates a virtual,common clock using a consensus approach
among multiple devices and then adjusts
the different local times of these devices.
He also presented an asynchronous
operation of this algorithm.
Dr. Sören Kerner (Fraunhofer IML)
presented their research on the PACE
Lab, a robotics 3D-data acquisition test
field featuring a high-precision motion
capturing system as well as softwaredefined radio system to develop 6G-driven
services in the context of the 6GEM
project. Within the PACE Lab, thesimulation-based digital twin reproduces
the experiment implemented in physicalspace in real time, including shadowing
effects by obstacles.
Mr. Niels König (Fraunhofer IPT)
presented their collaborative researchwith an interdisciplinary consortium on
manufacturing, cybersecurity, mobile
technology, and academia to analyze
security risks posed by 5G and to develop
measures for prevention, detection, andresponse at the 5G-Industry Campus■ Figure 9: Lecture from the German side
(Mr. Till Witt)Europe. Furthermore, he also presented
a testbed activity investigating mmW
in industrial applications, especially the
bandwidth implications on propagation,
performance, and use cases.
Dr. Renato Cavalcante (Fraunhofer
HHI) introduced the activities of the
6G Research and Innovation Center(6G-R IC). The highlights of theiractivities include verification experimentson the world’s first long-range D-band
system and channel charting for indoor
localization.
Dr. Dirk Wübben (University ofBremen) and Mr. Till Witt (NX P
Semiconductors) presented their researchon the integration of terrestrial and nonterrestrial networks. They are investigating
technical aspects such as functional split
and RAN placement among satellites,
HAPS, drones, and terrestrial systems andinformation-preserving compression for
efficient and reliable transmission.
Prof. Haris Gačanin (RWTH Aachen
University) presented their research on
the applications of machine learning inwireless communication. They developed
a prototype system to improve energy
efficiency by efficient utilization of FPGA
based on operational data and learning
functions.
Prof. Andreas Stöhr (Universit y
D u i s bu r g-E s s en) pr e s ente d t hei r
demonstrations on wireless communicationin THz band such as multi-beams serving
two users and high data rates of 200 Gbit/s.
Dr. Nida l Za r i feh ( Un iversit y
Duisburg-Essen) presented their researchon reliable THz connection in a smart
hospital. They are modelling THz
channels in a surgery room scenario
and conducting related measurements
and experiments to establish connection
between the THz access point and VR
headset.
Dr. Yuki Yoshida (NICT) presented
their research on data sharing between theGermany-Japan optical network testbeds
in a way that is compliant with utilization
policies that uphold data sovereignty, i.e.,
policies that are defined by the data owner,in order to accelerate research on networkAI.

Dr. Kentaro Fur usawa (NICT)
introduced a method for generating highquality terahertz reference signals fromlasers used for frequency standards using
compact, power-saving device calledmicrocomb, and reported on their efforts tofabricate and evaluate devices.
Prof. Sangyeop Lee (Tokyo Tech)
reported that they have fabricated andevaluated film-type absorber, reflector, andradome with characteristics of millimeterand terahertz-wave bands and obtained
favorable results.
Dr. Takahiro Kaji (NICT) presented
their research on radio-over-fiber (ROF),
which transmits terahertz frequency signals
using optical fibers. They have fabricateda D-band (110-170 GHz band) modulator
with antennas and demonstrated highspeed direct conversion between terahertz
waves and light.
Mr. Yoichi K ansaku ( JR East)
presented their research on an integrated
service that covers international tourism
experience to satisfy the end-to-end needsof inbound tourists in Japan. The service
supports tourists in online planning fromtheir country of departure and in guidingthem to their destinations after arrival.

which an RIS-equipped drone was used forangle-of-arrival estimation.
Prof. Ch r ist ia n Z enger (Ru h r
Un iv er sit y B o c hu m) pre s ente d ademonstration video on remote monitoringin security areas through the detection ofradio frequency signals using PHYSEC’s
anti-tamper radios. In case of physicalintrusion and destruction, the changes
detected in radio frequency signals triggera warning.
■ Figure 11: Demonstration by Prof.
Aydin Sezgin■ Figure 12: Demonstration by Prof.
Christian Zenger■ Figure 10: P oster session

8. Conclusion

7. Demonstration session

Two demonstrations were presented
by researchers from Germany. Both were
demonstrations that allowed participants
to experience the service and attracted wide
attention among the participants.
Prof. Aydin Sezgin (Ruhr University
Bochum) presented their research onreconfigurable intelligent surfaces (RIS).
They showed a demonstration video in

Lively discussions took place among
the participants in all the sessions,ref lecting the commitment of Japaneseand German researchers towards theadvancement of Beyond 5G/6G. It seemedthat research on the Japanese side focusedon important technological seeds, whilethat on the German side focused onservices that are easy to visualize. The keeninterest among the German researchers
in reducing energy consumption was
remarkable.
The 4th German-Japan Beyond 5G/6G
Research Workshop will be held from
July 1 to 4, 2024 in Berlin. It will be open
to anyone interested in Beyond 5G/6G
research activities, so we hope that many
people will be able to attend.

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